Readily replaceable electromagnet



l-2 ,1970 f A. R. LANG 3,508,182

READILY REPLACEABLE ELECTROMAGNET Filed- Feb. 6, 1968 Fig. 1.

INVENTOR.

ANDREW R. LANG A TTORNEY- United States Patent O 3,508,182 READILYREPLACEABLE ELECTROMAGNET Andrew R. Lang, Detroit, Mich., assiguor toBurroughs Corporation, Detroit, Mich., a corporation of Michigan FiledFeb. 6, 1968, Ser. No. 703,436 Int. Cl. H01f 7/20 US. Cl. 335-296 1Claim ABSTRACT OF THE DISCLOSURE An electromagnetic device in which thecore and coil are rigidly held together by a snap-action latch memberwhich is readily releasable to allow easy removal of the coil from thecore. The snap-action latch member is carried by a resilient pad whichis affixed to one end of the spool on which the coil is wrapped. In theassembled device the resilient pad is interposed between the spool and aweb which extends laterally from the magnetic core.

SUMMARY OF THE INVENTION The invention resides in the provision of anelectromagnet in which the core and coil are rigidly held together by asnap-acting latch member which is readily releasable to remove the coilfor replacement without need of removing the core, thus avoiding theneed for disassembling the supporting structure for the electromagnet.

In the drawings:

FIG. 1 is a fragmentary plan view of a device embodying features of theinvention;

FIG. 2 is a vertical sectional view partly in elevation, taken along theline 22 of FIG. 1;

FIG. 3 is an exploded perspective view of the electromagnet; and

FIG. 4 is a perspective view of an electromagnet.

Referring to the drawing by characters of reference, a supportingstructure for a row of solenoids 12 preferably comprises a pair of endplates 14 and a plurality of intermediate plates 16 rigidly securedtogether by parallel rods 18. The plates 16 are spaced apart and arespaced from the end plates 14 by suitable tubular spacer members. Anadditional rod 22 extends through and is supported by the plates 14 and16 and above and otIset from the rod 22 there is a stationary shaft 24which also extends through and is supported by the plates.

A plurality of supporting members 26 are provided for individuallysupporting the electromagnets 12 and are in turn mounted on thestationary shaft 22 and the rod 24, as illustrated in FIG. 2. Suitablespacers 28 on the shaft 22 and on the rod 24 hold the supporting membersrigidly in spaced apart relationship. An armature or clapper 30 isprovided for each of the electromagnets 12 and has downwardly directedside flanges 32 pivotally mounted on the stationary shaft 22, theclappers each overlying the upper ends of their respectiveelectromagnets 12. Pivoted on the shaft 22 there is a lever 36 for eachof the clappers 30, the levers being pivoted at their upper endsrespectively between the flanges 32 of the clappers 30, as shown inFIG. 1. Depending from the shaft 22, the levers 36 are biasedcounterclockwise by springs 38 which have one end connected to the lowerend of the lever 36 and the other end anchored to the supporting member26. Another spring 40 connects the lever 36 to one of the side flanges32 of the clapper 30.

Overlying each of the clappers 30 there is an amount rack 42, the amountracks extending longitudinally of the clappers, as shown. Each of theamount racks 42 is provided on its lower edge with a plurality ofnotches or teeth which represent positions in which the racks may bestopped by the clappers 30. As is well known, the positions in which theracks 42 are stopped by the clappers 30 represent amounts which may beprinted and also may be stored in a register (not shown). For a moredetailed description of the printing and storing of amountsrepresentative of the positions of the racks 42, reference may be had tothe patent of Robert S. Bradshaw, No. 2,822,752, issued Feb. 11, 1958.

In order to expedite the assembly of the supporting structure 10 and theelectromagnet 12 and to make it possible to replace an electromagnetwithout need of disassembling the support structure 10, I provide anelectromagnet in which the coil is readily separable from the core. T oaccomplish this, I form the supporting member 26 such that it has aU-shaped portion comprising up-- standing legs 44 and 46 joined by ahorizontal web 48. The leg 46 serves as the core and a tubular spool 50is readily slid down onto the core 46, the core being of sufficientlength to project slightly above the spool for engagement by the clapper30. The spool 50 has upper and lower end flanges 52 and 54 respectivelyto retain the required coil winding 56 therebetween. The spool may bemade of any suitable non-magnetic material, such as a suitable plasticmaterial.

Molded flat to the bottom of the spool flange 54 there is a plasticsheet 60 which rests on a seat 62 provided by the upper edge of the Web48, and carried by the spool 50 there is a depending latch member 64.The latch member is formed out of the sheet 60 which is a resilientplastic material so as to provide a resilient latch member which willflex laterally when its cam end portion 66 engages the seat 62 as theelectromagnet is pressed downward. When the cam 66 clears the lower edge68 of the web, the latch member 64 will snap into place under such edgewhich thus functions as a keeper. To remove the electromagnet 12 fromits core 46 it is only necessary to press the upper end of the coredownwardly while pressing upwardly against the bottom of the spool.

What is claimed is:

1. In an electromagnetic device, a mounting plate having a magnetic legto function as a magnetic core, a web joining said leg to the plateproper, a seat on said web laterally of said leg and defining a U-shapewith the opposed edges of said leg and the plate proper, a coil wrappedspool structurally independent of and surrounding said leg, a resilientpad aflixed to one end of said spool and apertured to receive said leg,said resilient pad resting on said seat, a latch keeper on the edge ofsaid web opposite said seat, and a resilient latch member carried bysaid resilient pad offset from the aperture and operable to snap intolatching relationship with said keeper by and upon pressing said spoolagainst said seat.

References Cited UNITED STATES PATENTS 3,238,485 3/1966 Litchfield etal. 335296 XR 3,191,135 6/1965 I-Iazelquist 33665 3,134,467 5/1964Blyth.

3,036,246 5/1962 Valleau 335-279 2,917,600 12/1959 Smith 335281XR2,513,965 7/1950 Pettit 335-296 XR BERNARD A. GILHEANY, Primary ExaminerD. M. MORGAN, Assistant Examiner US. Cl. X.R. 335281

